Grub2 configured & re-install display nothing?

[vzhen]

1. I edited 40_custom and sudo chmod -x /etc/grub.d/10_linux /etc/grub.d/30_osprober /etc/grub.d/???memtest

2. sudo update-grub and display nothing. (i guess i have wrong configured in 40_custom.

3. I completely remove grub-pc and re-install grub.
-I found that all the files in grub.d still there.
-I removed entire grub.d folder.

4. sudo update-grub and menu.lst display back my previous OS

5. I re-install grub-pc as well as uninstall grub.

6. sudo update-grub and
generating grub.cfg...........
Done <---- display NO OS here.

7. I thought grub.d folder will replace once i reinstall but it didn't

Question:
A. How can i re-install the default grub2 to detect all my OS?
B. How can i get back all the grub.d folder and the files inside
C. sudo chmod -x /etc/grub.d/10_linux to remove the execute.
How can i execute it back?

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I got Question C
sudo chmod -rwx


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FIXED with this thread - 12. Uninstalling grub2
http://ubuntuforums.org/showthread.php?t=1195275

Not sure we must copy those files or we must run under terminal to get this done